This proposal presents a binary system for the treatment of cancer using boron neutron capture therapy (BNCT). Boron-10, when activated by thermal neutrons, produces a fission reaction yielding highly destructive alpha particles. Incorporation of sufficient boron into structures that have a proclivity for melanoma cells is described. Monoclonal antibodies directed against melanoma-associated antigens will be covalently linked to boron-containing macromolecules. These together with other tumor-localizing compounds such as boron-containing chlorpromazine and porphyrins, either alone or in combination will be evaluated for their ability to deliver a critical number of boron-10 atoms (about 10-9) per cell and sustain a lethal n,Alpha reaction in vitro. Once this has been established, their in vivo tumor localizing properties will be determined in melanoma-bearing mice. These studies will lay the ground work for chemoradiotherapeutic trials in animals.